1. Field of the Invention
The present invention relates to a synthesizing method for a compound and to a catalyst for synthesis reaction. More particularly, the present invention relates to a synthesizing method for a compound by using a cross coupling reaction and to a catalyst for synthesis reaction used in that synthesizing method.
2. Description of the Prior Art
Cross-coupling reactions are the reaction to bond two compounds together. Of the cross-coupling reactions, the Suzuki cross-couplings, the Stille cross-couplings and the Heck cross-couplings are generally known as the cross coupling reaction using palladium as a catalyst for synthesis reaction.
For example, the Suzuki cross-couplings, which has a number of advantages of, for example, producing the synthesis of unsymmetrical biphenyl compounds without reacting with co-existing functional groups, permitting the reaction to proceed in the presence of water, and reducing the production of poisonous by-products, are widely used for synthesis of organic compounds having biphenyl skeletons and effectively used for the synthesis of e.g. medical products and the like (e.g. JP Laid-open (Unexamined) Patent Publication No. Hei 6-25175 and JP Publish No. Hei 6-508370 in Official Gazette publishing Japanese translation of PCT patent application).
In the Suzuki cross-couplings, palladium used as the catalyst for synthesis reaction is usually used in the form of an organic metal complex soluble in an organic solvent, such as tetrakis (triphenylphosphine) palladium.
Palladium is expensive and valuable and accordingly is desired to be collected after used for the reaction and recycled, for reduction in manufacturing cost.
However, in the practical reaction, palladium is used in the form of the organic metal complex soluble in the organic solvent, such as tetrakis (triphenylphosphine) palladium, as mentioned above. Due to this, it is practically difficult to collect the palladium after used for the reaction, so that the palladium is, in fact, wasted without being collected after used for the reaction.